1. Field of Invention
The invention relates to an EMI (electromagnetic interference) shielding device and, in particular, to an anti-EMI device that can shield EM (electromagnetic) waves.
2. Related Art
In observation of recent development in the electric information industry, particularly the wide uses of various electric information products, unnecessary voltages or currents exist among various internal systems of the compact electronic information product and produce many wide-frequency noises. Such noises seriously affect the functions of different parts. This phenomenon is normally called the EMI (electromagnetic interference). The EMI is a complicated problem in the computer manufacturing industry. The interference sources include the CPU (central processing unit), motors, inverters, relays, switches, transistors, amplifiers, power supplies or other exchange circuits.
To ensure operations of electronic products in normal EM environments, countries all over the world have started to implement EM controls, gauging the standards of many electronic, communication, scientific, industrial and medical instruments. Export or local products have to pass tests in certified EM compatibility laboratories before they can be sold on the market.
In general, the occurrence of EMI in electric information products may result from bad internal circuit designs or shielding. To solve the problems caused by the EMI in the prior art, one can either improve the circuit or use an EM wave shielding material to absorb or block EM waves. Such EM wave shielding materials include conductive shielding gaskets and metal foils. Currently, the conductive gasket used in the electronic products such as PC""s (personal computer), servers and mobiles has a long stripe structure. This structure is formed by wrapping a gasket with a conductive cloth. In addition to providing perfect EM wave shielding effects, the conductive gasket can even be made into different shapes to fit the configuration of all sorts of electric information products.
However, the conductive gasket still has several drawbacks in practice. For example, separate parts of an electric information device (e.g. upper and lower shells) often cannot be tightly connected, leaving a gap where EMI shielding is the weak. One is usually forced to attach conductive gaskets on the outer side of the sealing place. Since such conductive gaskets will be destroyed once the upper and lower shells are opened. One then has to attach new conductive gaskets, which may not fit very well. In view of the foregoing, it is highly desirable to provide an anti-EMI device used at the sealing interfaces of electronic devices, blocking leaking EM waves due to imperfect sealing and replacing traditional conductive gaskets to satisfy new safety laws imposed on electronic devices.
An objective of the invention is to provide an EM wave shielding device used at the sealing interfaces of electronic devices.
Another objective of the invention is to provide an anti-EMI device for electronic products to satisfy the EMI safety laws requirements.
In accordance with the above-mentioned objectives, the invention discloses an anti-EMI device for electronic products. The device includes a U-shape installation component and a spring component. The U-shape installation component is embedded inside the shell of the electronic product to fix and connect the anti-EMI device to the electronic product. The spring component is used to block the EMI of the electronic product. It is connected to the bottom plate of the U-shape component, extending along both sidewalls of the U-shape component toward the opening thereof and protruding from the electronic product shell. A tight elastic seal is formed between the upper and lower shells of the electronic product, effectively shielding the EM waves produced therein to satisfy the EMI safety requirements.